Thesis (M.D.S.)--University of Hong Kong, 2004.

Corrective feedback (CF) has been demonstrated in the literature to have a positive effect on language learners' grammatical accuracy in second-language (L2) writing. However, while much work has been done on feedback type (e.g. direct and indirect CF), studies continue to produce results which seem to contradict each other, indicating that a different focus might be useful. Moreover, much of the work on CF has been conducted with English majors or with participants studying (or preparing to study) in universities in English-speaking settings, but the generalisability of these studies to settings where English is neither the dominant language nor the learners' principal academic focus is unclear. The current study shifts the focus from type of CF to ways of facilitating CF use, exploring the issue with Korean L1 learners of English who are natural science majors at a university in South Korea taking a required English L2 writing course. The current study contributes to the body of knowledge on CF provision by quantitatively and qualitatively investigating how participants' use of feedback in this context is facilitated by their Western teachers, and how the effects of facilitated feedback use compares to effects in a group whose use of feedback is not facilitated. Working within a cognitive framework of language learning and using a quasi-experimental, mixed-methods, pre-test/post-test/delayed post-test study design, the study explores the differential effects of two ways of facilitating use of CF on the development of grammatical accuracy in written work, which was academic in style. Effects of these two methods of facilitating the use of CF are compared to effects of an unfacilitated condition. The hypothesis that learners would apply explicit knowledge to analyse and address errors in their writing, resulting in increased accuracy in the use of standard forms, is a cognitive one; and the facilitating of the interventions applies concepts from sociocultural theory. Participants in one facilitated condition received CF orally in individual conferences, with the teacher giving contingent assistance and only providing direct CF if needed; participants in the other facilitated condition received direct written CF, and were provided with worksheets designed to structure their independent reflection upon their writing. Finally, the Comparison Group received direct written CF without any facilitation. Measures of the development of accuracy focused on specific grammatical features targeted for instructional and feedback purposes, and assessed improvement in the accuracy in use of those features in new writing. The study applied a process-writing protocol: Write - Receive CF - Revise - Write a new paragraph. Effects of self-efficacy and language aptitude on the effectiveness of the treatments are also considered. Quantitative analyses of the data suggest that providing direct written CF without facilitating its use enabled the development of accuracy equally as well as CF whose use was facilitated, whether by the conferences or the reflective worksheets. Qualitative analyses reveal how teachers facilitated the use of CF in conferences, and how students participated in both forms of facilitation. Findings suggest that previous educational experience may influence learners' ability to effectively use facilitated CF. Finally, interviews with participating teachers and students provide insight into both parties' experiences with these interventions, contributing to knowledge about intervention development and implementation, both in research and in classroom settings.

Indiana University-Purdue University Indianapolis (IUPUI) / This investigation was designed to compare the force (grams) required to overcome a simulated cuspid retraction assembly capable of three dimensional control during the retraction process. It was hypothesized that a significant difference in the mean retraction values exists between the newer orthodontic alloys of Nitinol, Beta-Titanium, as well as Stainless Steel. One hundred eighty bracket and archwire combinations were examined as follows: Sample # Wire Cross-section Wire Material 30 .016”x.022” Stainless Steel 30 .017”x.025” ” 30 .016”x.022” Nitinol 30 .017”x.025” ” 30 .016”x.022 Beta-Titanium (TMA) 30 .017”x.025” ” A statistically significant difference was shown to exist between all six groups examined regarding the variables of wire size and wire material. The statistical analysis revealed that increasing rectangular archwire cross-sectional size from .016"x.022" to .017"x.025” rectangular wire when simulating canine retraction using an .018" slotted Lewis bracket will lead to significantly greater functional forces. The analysis of wire materials indicated that a significant difference (p=.01) exists between rectangular Beta-Titanium (TMA), Nitinol, and stainless steel during simulated cuspid retraction utilizing a narrow .018" Lewis bracket ligated with A-lastik ligatures. The least frictional force was observed with the .016"x.022" stainless steel test cells. The largest frictional force was found in the .017”'x.025" Beta-Titanium retraction specimens. Nitinol revealed force data intermediate between stainless steel and Beta-Titanium. The maximum resistance assembly developed 2.3 times the minimum frictional force observed. The mean grams of frictional force within these test cells ranged from 55.03 grams for the .016"x.022" retraction assembly to 132.68 grams for the .017"x.025" Beta-Titanium assembly. A topographical scanning electron microscope survey of the brackets and archwires utilized was included to provide qualitative insights into the quantitative results described.

Thesis (M.Sc.D.)--Boston University School of Graduate Dentistry, 1972. (Orthodontics) / Bibliography included. / The present study was undertaken to document the incidecnce of the relapse phenomena taking place up to two years after completion of active orthodontic therapy. This paper was limited specifically to the post treatment changes of the mandibular plane. The study was carried out on the records of thirty-six patients treated in the orthodontic clinic at Boston University School of Graduate Dentistry. Original, final, and two year post treatment cephalograms, pano-graphs, and study models were evaluated and compared for each patient. Observations of the compiled data revealed that twelve of the thirty-six patients showed a decrease in the mandibular plane angle during treatment, while ten patients showed an increase. Further analysis of the results revealed that the majority (70%) of the patients with the increased mandibular plane angle showed a decrease during the retention period, reverting back to or toward pretreatment values. Of the twelve patients experiencing a decrease during treatment, the post treatment results were more varied, and no definite trends could be observed. Further study is needed to determine if an increase in the mandibular plane angle during orthodontic treatment is nonphysiologic and, therefore, more susceptible to relapse.

Thesis (M.Sc.D.)--Boston University School of Graduate Dentistry, 1972 (Orthodontics) / Bibliography included. / The present study was undertaken to compare the efficiency of three different biomechanical mechanisms in preserving mandibular molar anchorage. Thirty-five patients were treated with intercanine coil, lip bumper, 9r mandibular cervical traction through the end of cuspid retraction. Midtreatment cephalograms were then taken. Superimposition of these midtreatment cepbalograms with the pretreatment cephalograms provided the author with the net mesial or distal movement of the mandibular first molar in each case. The data obtained from each case was accordingly placed in the appropriate biomechanical group. Each group was then statistically related to one another by means of the Mann-Whitney U Test. It was found that a stastically significant difference existed between lower cervical traction and the intercanine coil. The confidence level obtained (P < .02) indicated that less than two cases out of a hundred had a chance of coming from the same population. This data also showed a mean increase in mandibular anchorage with lower cervical traction ( +.062 mm. gained) indicating that there may be very good possibilities for this system to be used in orthodontic cases when anchorage is of a critical nature.

Thesis (M.S.)--University of Louisville, 1997. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Southern California, 1996. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Louisville, 1997. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (doctoral)--Westfälische Wilhelms-Universität, Münster, Germany.

Thesis (doctoral)--Westfälische Wilhelms-Universität, Münster, Germany.